A Bangladeshi worker poses at a brick factory on the outskirts of Khulna, in Bangladesh. Khulna's population declined by 11% between 2001 and 2011 as it lost its jute industry. Photo: AFP / Munir uz Zaman

Urbanization has been a well-established trend in the 20th and 21st centuries. However, de-population and de-urbanization in some places are becoming serious problems for which no good solutions exist at present.

People have steadily moved from rural to urban areas to improve their standard of living and quality of life. In 1950, 30% of the world’s population was urban. A century later, 66% of people are expected to live in urban areas. In terms of absolute numbers, the difference is stark. In 1950, 746 million people lived in urban areas. By 2046, it is estimated to be over 6 billion.

Not surprisingly, global attention has focused on this rapid century-long urbanization process and its social, economic and environmental implications. In contrast, de-urbanization receives limited attention. If one searches Google for “de-urbanization,” the response is “Did you mean: urbanization?”

Reasons for shrinking cities

De-urbanization happens for three main reasons. First, when the fertility rate of a country dips below 2.1, its total population, including its urban population, starts to decline. Fertility rates in South Korea are now 1.17, and in Japan 1.44. Without immigration, a fertility rate of 2.1 is needed to have a stable population. If current trends continue, Japan’s population is expected to decline from 126.5 million at present to 88 million in 2065, 51 million by 2115, and to zero by around 3000!

Second, in many cities, jobs in sectors such as manufacturing and mining are disappearing. Between 1950 and 2010, many US cities decreased in population: St Louis (by 62.7%), Cleveland (56.6%), Pittsburgh (54.8%) and Cincinnati (41.1%).

Third, some cities have lost population because of resource depletion or technological changes. Yichun, a city in northeastern China close to the Russian border, was transformed from a sleepy to a bustling town by unsustainable logging. Later between 2012 and 2016, Yichun lost 12% of its population because of depletion of natural resources.

Lessons from China

China’s voracious appetite for natural resources to fuel its unprecedented continuous economic growth over the past three decades has meant that some 500 billion metric tons of resources, ranging from coal and iron ore to gold, have to be mined every year. Resource exhaustion and environmental degradation have contributed to rapid de-population in many urban centers.

China’s National Development and Reform Commission has reported that 50 of China’s 390 mining towns have already exhausted their resources that can be economically extracted. This has left 3 million people jobless, affecting an additional 10 million people.

The commission has given 44 cities the official status of being “resource depleted.” These cities are receiving central-government funding to rejuvenate and restructure their economies by increasing employment opportunities and improving environmental conditions. More cities will earn this distinction unless natural resource management and environmental protection policies measures are formulated over a long-term basis.

Technological development and economic considerations can also contribute to de-urbanization. For example, Khulna, Bangladesh’s third-largest city, grew 20-fold between 1950 and 2000. Then, as its jute industry declined, it lost more than 150,000 people (11% of its population) from 2001 to 2011.

Infrastructure and shrinking cities

Throughout history, as populations increased and urbanization took place, all types of infrastructure – for water, energy and transportation – have had to be built to meet steadily expanding needs. All societies have had centuries of experience of how to expand infrastructural requirements. Considerable expertise and technology have been developed to meet these advancing needs.

What we are facing now is a different type of problem that is becoming increasingly familiar in both developed and developing countries. How can shrinking cities downsize the existing infrastructure that has already been built and find a usable financial model for operating and maintaining them?

Take Leipzig, Germany. During the post-1990 period, numerous buildings were renovated, water-efficient toilets and showers were installed and piped water and wastewater facilities were increased by 50%. Consequently, leak detection and repairs received priority, and water tariffs were increased to finance the necessary infrastructure expansion and modernization. All these contributed to major changes in people’s perceptions of the importance of water conservation.

A system that was initially designed to provide 200 liters of clean water per person per day dropped to only 92 liters. Fewer users, increased efficiency and less water demand by industries dramatically reduced water demands from 700,000 cubic meters to only 165,000 cubic meters per day. This means Leipzig now has a similar water demand to what it had in the mid-1940s but a supply network that is significantly above what is needed.

In China, resource exhaustion and environmental degradation have contributed to rapid de-population in many urban centers

This has created new types of challenges. Lower demand means water stays in the pipes for longer periods, increasing the risk of bacterial growth and microbial contamination, and thus health problems. Lower water use means lower waste-water generation. This contributes to sedimentation in sewer pipes because of low flow velocities. Thus clean water has to be used to flush the sewer system periodically for proper maintenance.

Leipzig’s water utility is facing higher operation and maintenance costs, and also higher long-term investment costs for restructuring the water system, due to declining consumption and revenues.

Another problem is that these unexpected but serious financial pressures are forcing the utility to focus on possible technical fixes due to lower domestic and industrial water use. Lower priority given to proper operation and maintenance practices will negatively impact the long-term sustainability of the utility.

Such countries as Japan and South Korea, and numerous cities around the world, are currently facing similar problems in downsizing their current infrastructure to meet reduced demands from their citizens and industries. Prosperous cities such as Singapore now have to consolidate schools as the number of students in each has declined. All the resource-depleted cities of China will have to consider how best to balance their infrastructure with decreased demands.

This is an issue that needs urgent attention from policymakers and researchers, especially in countries and cities where de-urbanization has become a more serious problem than urbanization. Within the next decade, cost-effective solutions will have to be found.

Asit K Biswas is a distinguished visiting professor at the Lee Kuan Yew School of Public Policy at the National University of SingaporeCecilia Tortajada is a senior research fellow at the school; Martin Stavenhagen is climate, energy and water policy consultant at the National University of Singapore. This article was originally published on The Conversation. Read the original article here.